<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>百度一下</title>
</head>
<body>
  <form action="http://www.baidu.com/s">
    <input type="text" name="wd" />
    <button type="submit">百度一下</button>
  </form>
</body>
</html>